The present invention relates to a laser diode formed with a semiconductor substrate in which a strip-shaped laser active zone is provided.
From "Electronics Letters", Volume 18 (1982), pages 631 and following, incorporated herein by reference, a laser diode is known which as is the case with the diode of this invention, is provided for coupling to a glass fiber serving for radiation transmission. The laser diode described in greater detail in this publication in Figure 2 is soldered on a heat sink which is a silicon substrate. A V-shaped groove is introduced into the material of the heat sink which serves for accommodating the solder. This groove, for which a width of 75 .mu.m is disclosed, and the substrate of the actual diode disposed thereabove, are so aligned relative to one another that the surface of this groove and the laser-active zone lie precisely above one another. The surface of a portion of the heat sink has additional grooves running partially transversely thereto, which are likewise provided for a flowing of the solder. For the accommodation of a supply of the particular solder which is later to fill the grooves, a corresponding recess is provided in the heat sink.
In this publication, it is also stated that thermal expansions are very disadvantageous for the life of a laser. In this publication, the solution to this problem is visualized as being restricted to the use of silicon for the heat sink and the use of the above described grooves.